Recent years have seen the importance of the role of innate immunity grow, commensurate with the increase in various diseases associated with the diversification of lifestyles. A study by Steven B. Mizel in one of the U.S. NIH grants projects revealed that a plague bacillus (Yersinia pestis) vaccine fused to a flagellin, one of the innate immunity ligands, increases an adjuvant effect to the vaccine thereof to about 500,000 times. This result suggests a potential magnitude of innate immunity generating an expectation for adjuvant effects of innate immunity ligands (See Non-Patent References 1 and 2).
Innate immunity receptors or similar sensors thereof are widely present in animals, plants, and microorganisms. Specifically, for the vertebrate innate immune receptors, TLR (Toll-like-receptor), NLR (Nod-like-receptor), and RLR (RIG-like-receptor) are present in or out of the cells, whereby these detect foreign invaders such as bacteria and viruses by way of substances (ligands) formed by degradation of bacteria, viruses and the like and identify them by pattern recognition. Ligands are produced in multiples depending on the types of bacteria and viruses, generally, varying in substance and concentration that are generated, resulting in an identification and an innate immunity response, with a subtly different pattern recognition dictated by a combination of their ligand groups.
Innate immune response cells, such as epithelial cells in humans, have TLR TLR-1 & 2, TLR-6 & 2, TLR-4 & MD-2, and TLR-5 act on the cell membrane; and bacterial or viral nucleic acids (DNA and/or RNA) degradation fragments from degeneration by lysosomal enzymes in the endosome or phagocytic phagosome activate TLR-3, TLR-7, TLR-8, and TLR-9. At work in the cytoplasm are NLR receptors that sense low molecular degradation products of bacteria such as NOD1 NOD2, NALP3, and NAIP5, IPAF, and RIG; and MDA-5, and the like that sense viral low molecular degradation products and/or nucleic acids.
These receptors, sensors of innate immunity, release interleukins and/or type I interferons (IFN-α family, IFN-β and IFN-λ) or substances analogous thereto, for various antibacterial effects according to the combination of patterns of sensed degradation products of the respective bacteria and/or viruses thereof, thereby causing the neighboring cells to sense them. Upon sensing these substances, the cells simultaneously release antibacterials such as defensin, cathelicidine, and dermicidin and/or a group of antiviral substances, as many as several hundred types, called the ISG, thereby defending a group of friendly cells from the foreign invaders. Herein, the fact that living organisms release a large number of antiviral substances in countering the rapidly changing viruses has turned out to be one of the reasons that require the composition of the instant invention.
The second role of the innate immune receptors is to activate phagocytes present in a multicellular organism with a gut. Phagocytes have developed as cells with a shared responsibility of the moving innate immunity, in which its role is played in humans by macrophages, neutrophils, or the like. Macrophages particularly play important roles as commanders of the innate immune system. When receptors, innate immunity sensors, are stimulated, macrophages, neutrophils, and their peers are activated, launching a framework to fight off invaders such as bacteria and viruses.
Vertebrates, except for lampreys and hagfish, have developed a lymphocytic immune system that identifies self from non-self, reinforcing the immune system. In particular, the mammalian lymphoid immune system has undergone a sophistication and enhancement on the basis of a complement system. On the other hand, this has resulted in patients suffering from allergic and autoimmune diseases.
In particular, in mammals, when the receptors of innate immune response cells such as macrophages, dendritic cells, Langerhans cells, and microglia sense the presence of a respective ligand (stimulus-specific), this leads to the secretion, in accordance with the resultant pattern recognition, of interleukins such as IL-12, IL-6, IL-4, and TGF-β that prompt T cell differentiation; IL-1β and IL-23; and IL-2 that activate the differentiated T cells; and IL-25, IL-27, and IL-6, that suppress the activities of the differentiated T cells.
These processes have IL-21 release from Th17 or natural killer T cells bringing to apoptosis, or suppressing, B cells and memory T cells that have antibodies that attack the self thereby preventing autoimmune diseases from developing.
It has been clarified by kinetic analyses of RNAs expressed from DNA by microarrays that various combinations of the innate immunity ligands, combinations of antigens and innate immunity ligands, and the like lead to variety of changes to the processes and differences in actions thereof. This is because technological advances in kinetic analyses of DNAs and RNAs have permitted capturing changes, in time sequence thereof, of the expression process of innate immunity and lymphocyte immune system (the so-called acquired immunity), the apoptosis pathway, inflammation controls (anti-bacterial, anti-cancer) pathway, switching to an antiviral pathway, inflammation and inflammation control processes, and the like.
Elucidation of such innate immunity receptors TLR, NLR, and RLR and of subsequent physiological processes thereof holds the potential to revolutionize medicine. It therefore provides hope for paving the way to an ultimate solution to such problems that conventional medicine finds difficult to treat, such as “various types of cancer afflictions and/or polyp formation in precancerous stages”, “viral diseases such as HIV, HCV, HPV, and HHV, and new type influenza” and “antibiotics-resistant bacteria and bacteria latent in the body,” “inflammatory diseases such as various allergic diseases”, and “various autoimmune inflammatory diseases.”
Against the background of such a flow of technology, A. “Effective combination of innate immunity ligands” and B “The combination of antigen vaccines and innate immunity ligands” have come to have an extremely important meaning.
Among those that have been popularized in the past for innate immune ligands are, for example, LPS, R-848, imidazoquinoline, and flagellin. LPS is a ligand that activates TLR4 and MD2; imidazoquinoline and its derivatives are ligands that activate TLR7; and flagellin is a ligand that activates TLR5.
Although both imidazoquinoline and R-848 exhibit the same TLR activity, they produce different IFN-α types such that imidazoquinoline is used as a therapeutic agent for HPV (papillomavirus) while R-848 is used for HHV (herpes virus). This shows that even those agents with the same acceptor activity may exhibit different effects due to different ligands.
In addition, MDP (muramyl dipeptide) and its derivatives are innate immunity ligands noted since about 1985, and they activate TLR-2. MDP-Lys, a derivative thereof, is a pharmaceutical agent as an adjuvant. This has recently received renewed attention for its activation of NLRs, but it is never used alone. It has been noted that a combination with other ligands such as LPS, Lipid A, or the like can elevate its ligand effect.
In addition, Patent Reference 1 has a finding that IL-10 is unexpectedly produced with a complex ligand made up of IL-12-producing bacteria and/or yeast with non-IL-12-producing bacteria and/or yeast.
Thus, complex ligands provide a synergistic effect absent in single ligands, in addition, permit the sites of action thereof to be diversified, thereby allowing the LPS (endotoxin) as a ligand to spread its risks, if it had any negative effect at all. A reason such as this has led to a strong need to develop a complexly-working ligand. In particular effects of such ligands have come to have an important significance after the discovery of flagellin's powerful adjuvant effects.
Modern health care is up against a wall. Antibiotics that have been relied upon are ineffective for viruses and face serious problems of generating resistant-bacteria. There is also the side effect of anaphylaxis. Hormones, such as steroids, and immunosuppressive drugs increase the risks of pathogenic and/or opportunistic bacterial infection through the weakening of the immunity, with their use failing to restore living organisms including the human life to normal. In addition, it has also been strongly pointed out that treatment with inhibitors also suffers from adverse effects by hindering the normal living organism's systems. A continued use of ineffective drugs is also escalating health care costs. Also from the standpoint of dismantling this wall, a safe and outstanding innate immunity-active ligand is being sought.